For custom harnesses and partition regions, there should be the ability to place multiple synth IO tiles at the same VPR coordinate, connecting to different wires at the border of the ROI.

I think this can be implemented relatively easily using by increasing the tile capacity, but I am unsure how to handle an INPAD and and OUTPAD at the same vpr coordinate. My initial thought is to merge these together into an SYN-IOPAD and maybe have the INPAD and OUTPAD as equivalent sites.